1. Field of the Invention
This invention relates generally to a cleaning device for cleaning an article to be cleaned, such as a semiconductor wafer in a cleaning tub, and more particularly to such a cleaning device that can always keep clean atmosphere around the cleaning tub.
2. Description of the Related Art
A semiconductor wafer is subjected to various cleaning processes, such as a washing process, an ammonia process, fluoric acid process, and so forth. A device in which such processes are performed has a cleaning tub for a cleaning liquid, such as pure water. In the cleaning liquid contained in the cleaning tub, a semiconductor wafer is dipped and washed.
Some cleaning devices of this type have cleaning tubs in their chambers in order to prevent an cleaning liquids from being scattered on the outside of the chamber and prevent external fine particles, etc. from entering the chamber. A shutter which can be opened/closed is installed at the entrance portion of each chamber so that the semiconductor wafer can be taken in/out.
In this case, however, when the shutter is opened to take the wafer in/out of the chamber, an atmosphere can easily leak out of the chamber. In particular, in the case of using chemicals, as a cleaning liquid, heated at about 80.degree. C., the vapor of the chemicals may cause environmental pollution. Moreover, fine particles are generated from a mechanical portion which carries the semiconductor wafer in the chamber and conveys it in/out of the cleaning tub, and an atmosphere containing the fine particles can easily enter in the chamber. As a result, many foreign objects are adhered on the semiconductor wafer and the yield of semiconductor products is decreased.